Integrated Diseased Management on Coffee Wilt Disease Caused by Fusarium Xylarioides and its distribution in Ethiopian Review
Asmamaw Kassahun Wassie*
Bihar Agricultural University, Sabour, India
Submission: July 11, 2019 Published: November 12, 2019
*Corresponding author:Asmamaw Kasahen, Debre Tabor University, Department of Plant sciences, Plant pathologist Lecturer, Agriculture and Environmental Sciences Faculty, Director of research and publication, Email:-firstname.lastname@example.org , Tell: +251911065399, Debre Tabor University, Po Box 272, Debre Tabor, Ethiopia
How to cite this article: Asmamaw Kasahen. Integrated Diseased Management on Coffee Wilt Disease Caused by Fusarium Xylarioides and its Mangement Option Review. Agri Res& Tech: Open Access J. 2019; 22(4): 556232. DOI: 10.19080/ARTOAJ.2019.22.556232
Coffee belongs to the family Rubiaceae, which is widely distributed throughout the tropical region. Ethiopia the center of origin for Coffea arabica. Coffea arabica originates from Southwest Ethiopia Keffa. Coffea arabica very important for local people as a cash crop for the local and international market. Coffee arabica is attack by several diseases among these major diseases are coffee berry disease, coffee wilt disease, coffee leaf rust are the major fungal diseases to reduced yield of coffee in the country. Coffee wilt disease caused by fungal pathogen that affect vascular wilt disease, it was the main factor of coffee tree death in different coffee growing regions, with national average disease incidence 28% and severity 5%. Coffee wilt disease is a soil-borne pathogen, and this presents difficulties in the application of chemical treatments; affected fields to be left as fallow for some years or other crops planted. Currently in coffee trees are less productive because of variable factors, among that diseases are the major constraints which threatening coffee genetic resources. These diseases are occurring with varying degree of infestation and distribution in the Ethiopia. Thus, the coffee conservation strategies should take the disease into account and apply the recommended principles and practices of disease management. Integrated disease management for coffee Fusarium wilts, one of the most devastating and challenging type of diseases impairing agricultural production worldwide, based on the IPM, (i) use of pathogen-free planting material;
(ii) site selection to avoid planting into high risk soils;
(iii) reduction or elimination of F. oxysporum inoculum in soil;
(iv) use of biocontrol agents for protection of healthy planting material from infection. Based on our review findings suggest resistant coffee varieties through large-scale collection and screening against the pathogen would be inevitable for increase coffee yield.
Coffee belongs to the family Rubiaceae, which is widely distributed throughout the tropical region. Although there are many species of coffee, the two commercially important ones are Coffea arabica and Coffea robusta Pieters & Van der Graff . Both species can grow best on deep, free- draining, loamy soils, with a good water holding capacity and a slightly acid soil (pH 5-6) and soil fertility is important for good production of coffee Lewis Ivey . Coffee has rapidly become one of the prominent commodity crops in global transactions, and it stands first in earning foreign currency for many countries including Ethiopia. Ethiopia has the longest tradition of coffee production and consumption in the world with a traditional way of cultivation and the performance of inimitable ‘coffee ceremony’. Coffee is crucial to the Ethiopian economy because it contributes 10% of the country’s gross domestic product
and generates more than 40% foreign exchange earnings. Coffee remains crucial to the biological, social and economic values of the country, but despite being the birthplace of coffee, Ethiopia has not exploited and benefited from the crop to the best of its genetic and ecological potential.
Coffee production systems remain predominantly traditional, and diseases and insect pests greatly reduce the productivity and quality of the produce. Historically, Coffee Wilt Disease (CWD) on C. arabica was first observed in Ethiopia by Stewart , who described the wilting symptom and also identified the causal organism to be Fusarium oxysporum f.sp. coffeae. Later, based on comparative studies of the isolates collected from dying Arabica coffee trees from different origins and different Coffea spp., the causal was confirmed to be Gibberella xylarioides Heim & Saccas, of which Fusarium xylarioides Steyaert is the imperfect (conidial)
state Kranz & Mogk . Van der Graaff & Pieters  reported that
this pathogen caused a typical vascular wilt disease and was the
main factor of coffee tree death in Ethiopia. During recent years,
the prevalence and importance of CWD have been markedly increasing
throughout coffee producing areas of the country Girma
& Oduor [6,7]. Besides drastic reduction in average yield, the crop
is attacked by several diseases, among that coffee leaf rust; coffee
berry disease and coffee wilt disease are the major fungal diseases
contributing to reduced yield in the country.
Coffee is the most important cash crop for Africa as a whole,
contributing some 10% of the total foreign exchange earnings in
the continent. A number of coffee-producing countries in Ethiopia
depend on the export of this commodity for more than half of their
foreign exchange earnings Phiri. Arabica coffee has become a major
global commodity which accounts for 66 percent of the world
coffee market. Coffee production in Ethiopia is broadly grouped
into four systems on the basis of biological diversity of the species
and level of management, namely, forest, semi-forest, garden and
plantation coffee Meyer & Paulos [8,9]. More importantly, majority
of the coffee farmers in the producing countries are small scale
growers who primarily depend on coffee for their livelihood. Its
cultivation, processing and transportation provide employment
for millions of people. The average yield in Ethiopia is low (about
700kg/ha per year) which is half of that achieved.
Trachemys’s or vascular wilt of coffee historically was first observed
in 1927 on Coffea excelsa in Central Africa Republic and first
reported in 1946 and the causal agent was identified as (Fusarium
xylarioides) by Steyaert, Girma Adugna . Coffee wilt disease was
first observed in Ethiopia in the Kaff Province by Stewart , who
described a wilting of C. arabica and mistakenly classified it as Fusarium
oxysporum f. sp. coffeae. Lejeune also noted the presence
of this disease on Arabica coffee. Later, the causative agent of the
disease was confirmed to be Fusarium xylarioides Kranz & Mogk
. The pathogen also attacks Coffea arabica and is endemic in all
coffee growing areas of Ethiopia. During the 1950s and 1960s, it
was considered to be the most serious disease of coffee in Africa
and destroyed millions of coffee trees Oduor . Coffee Wilt Disease
(CWD), which is caused by Fusarium xylaroides Steyaert, the
conidial stage of Gibberella xylarioides Hem. & Saccas is the most
serious problem of Robusta coffee (Coffea canephora) production
in Ethiopian. Coffee wilt disease the main symptoms are yellowing
and collapsing. The disease enters through a low surface wound or
a shallow root. Afterwards the connecting vascular strands in the
stem are discoloured violet brown to black in a broad, hardened
band. CWD occurs in all of the above coffee production systems
to varying extent of damage among and within coffee fields and
districts (Woredas) depending on different interacting factors,
mainly susceptibility of coffee trees, intensity of cultural practices
and environmental conditions Merdassa . CWD, for many
years remained as an endemic disease of Coffee arabica but has
gained importance over time in almost all coffee-growing regions.
The nationwide biological survey of CWD showed that on average,
27.9% of 1607 sample coffee farms were affected, with disease incidence
ranging from 15% to 34.0% and disease severities varying
between 1.3% and 5.0% Oduor .
The pathogen survives in the soil in the form of microconidia,
macroconidia, chlamydospores and perithecium with ascospores.
The pathogen appears to be a soil inhabiting fungus which can
penetrate through wounds either above or below ground. Inside
the coffee the fungus invades the water conducting system (xylem)
and blocks the movement of water upwards from the roots
to the rest of the plant. The timing from first symptoms to death of
the tree varies from days in young plants to eight months in trees
more than ten years old. Once the fungus infects the coffee tree, all
affected trees eventually die Girma Adugna. When seedlings with
healthy roots are transplanted into either naturally or artificially
infested soils, no wilting symptoms appeared. Infection exhibits
when the tap roots are injured and transplanted into naturally or
artificially infested soils, and also only on those seedlings inoculated
by stem wounding through ditching with F. xylarioides infested
scalps or by injecting the conidial suspensions with needles Lewis
Ivey. The stem nicking or root drenching inoculation methods
also elaborate the roles of contaminated farm implements in cross
inoculating coffee trees as well as disseminating the coffee wilt
pathogen in the field CABI .
Coffee suffers from a range of co-evolved diseases including
Coffee Berry Disease (CBD), Coffee Wilt Disease (CWD) and Coffee
Leaf Rust (CLR) caused by Colletotrichum kahawae, Gibberella xylarioides
and Hemileia vastatrix, respectively. From those Disease
Coffee Wilt Disease is sever affect the growth of coffee, its nature
soil-borne pathogen and this presents difficulties in the application
of chemical treatments; affected fields may need to be left as
fallow for some years or other crops planted. For diseases caused
by soil-borne pathogens, such as Fusarium wilts, which are mainly
monocyclic in nature, this disease continued reliance on unproductive
coffee varieties, the widespread and prevalence of pests
and diseases. Integrated Disease Management programs are based
on the following principles of disease control Coffee Wilt Disease:
those method are the control principles
a) Exclusion of the pathogen or
b) Eradication, of the pathogen;
c) Escape from infection;
d) Development and use of genetic resistance against the
e) Protection of the plant from infection; and
f) Reduction of disease in infected plants.
They can be applied by biological, chemicals, cultural, physical,
and regulatory methods, depending of the nature of the agents
employed and methods should be targeted to excluding the pathogen,
as well as reducing the amount and/or efficiency of the initial
Therefore, IDM strategies of those Coffee Wilt diseases within
the framework of sustainable agriculture would include:
(i) Use of pathogen-free planting material;
(ii) Site selection to avoid planting into high risk soils;
(iii) Reduction or elimination of F. exospore inoculum in soil;
(iv) Use of biocontrol agents for protection of healthy planting
material from infection by resident or incoming inoculum subsequent
(v) Use of resistant cultivars regardless the level of resistance;
(vi) Choice of cropping practices to avoid conditions favoring
infection of the plant.
Fusaria can be transmitted in infected seeds, vegetative propagated
planting material (e.g., bulbs, cuttings, rootstocks, scions, etc.),
or transplants developed from them. Use of infected propagating
material can lead to introducing the pathogen or its pathogenic
variants into pathogen-free production areas or pathogen-free
soils in areas where the pathogen occurs already. Therefore, the
importance of checking the health of that material through certification
programs, phytosanitary inspection, and quarantine legislation
cannot be too strongly emphasized. Failure in this pursue
may lead to the establishment of new pathogens in a country, as it
recently happened in Spain with Fusarium circinatum, F. oxysporum
f. sp. basilici, F. oxysporum f. sp. radicis-lycopercisi, Fusarium
solani f. sp. cucurbitae race 1, etc. More importantly, introduced
exotic pathogens can potentially be invasive and give rise to devastation
in cultivated as well as natural plant communities. The Plant
Protection Organization (EPPO), being well aware of such a risk,
has placed a warning on quarantine fungal pathogens, of which
21 species are already present in member states and 39 are currently
absent from them One of most important difficulties for the
detection and identification of Fusarium wilt pathogens concerns
the similarity in morphology between pathogenic and non-pathogenic
strains of F. oxysporum.
Proper selection of the planting site optimizes the use of
F.oxysporum ff. spp.-free planting material in non-infested soils.
For that purpose, accurate information on the disease history of
the field with regard to production of susceptible crops is of utmost
importance. Disease risk assessment based on Inoculum
Density (ID) Disease Incidence (DI) relationships would be most
useful if the inoculum density in soil at planting sites could be estimated
to avoid those with high risk for severe disease. Populations
of F. oxysporum in soil can be assessed by soil dilution plating using
selective media. However, this does not allow inferring ID of
pathogenic strains because of their morphological similarity with
non-pathogenic ones. For example, De Vay et al. assessed the ID of
F. oxysporum in cotton soils by agar dilution plating but identified
colonies belonging to F. oxysporum f. sp. vasinfectumby further
pathogenicity assay to cotton seedlings. That allowed estimating
the number of F. oxysporum f. sp. vasinfectum Colony Forming
Units (CFU) g-1 soil and relating a range of 1,100 to 2,608 CFU g-1
soil to increase of Fusarium wilt incidence over physiological time
in degree days and effects on crop growth and yield. Ben Yephet
used a similar approach for Fusarium wilt in carnations and found
that 6, 25, 120, 770, and 3,500 CFU g-1soil of F. oxysporum f. sp.
dianthi determined a final DI of 2, 5, 13, 34, and 57 %, respectively;
the flower yield being related inversely to ID of the pathogen.
Conversely, disease risk can be made by directly bio-assaying the
planting soil with susceptible and resistant host cultivars.
These are undoubtedly the
most feasible option for controlling CWD in all affected countries.
Use of resistant cultivars was found to be highly effective when
combined with other control measures during the previous outbreak
of the disease. The combined use of selected cultivars and
biocontrol agents can provide better disease control than the use
of any of them alone. It has been reported that varietal differences
in resistance to the pathogen and suggested the use of resistant
varieties as a means of control. However, developing resistant varieties
is long-term and requires considerable resources (human,
facilities and financial). Megan reported that Uganda has advanced
further with its CWD breeding programme, using single-tree selection,
and some of the more promising selections are currently
being evaluated on-farm. The DRC is also trying to select varieties
for CWD-resistance. This method was very successful in controlling
outbreaks of the disease in 1950s and 1960s in West and
Central Africa, where affected coffee is uprooted and destroyed
and the fields replanted with resistant cultivars of C. canephora
such as cultivar `robust`, but recently resistance is broken down
due to emergence of a new form of the fungus Meseret Wondimu
also reported apparent differences for the same materials planted
in different areas of the region, i.e. certain C. liberica and C. canephora
varieties showing resistance in Ivory Coast were completely
susceptible in CAR, suggesting the resistance was either
being influenced by environmental conditions or there were different
physiological races of the pathogen in different localities
of this region. Vander Graaff & Pieters  reported that coffee lines of C. arabica in Ethiopia showed differences in resistance to
the CWD pathogen, thus providing potential for controlling CWD
using resistant varieties in Arabica coffee. They suggested that resistance
in C. arabica was quantitative in nature and horizontal,
and there was no evidence of single-gene (vertical) resistance that
could be readily overcome by pathogen adaptation.
Unlike with other coffee diseases, namely,
CBD and CLR, coffee trees infected by CWD cannot be saved.
Successful control of the disease depends on the principles of
disease prevention (avoid wounding of any part of the plant) and
phytosanitation. The conventional phytosanitary approach of uprooting
and burning the whole infected coffee tree on the spot is
strongly recommended to coffee farmers to contain the disease as
soon as symptoms are seen, but this relies on early diagnosis. Use
of CWD-infected trees for any purpose is prohibited and replanting
with susceptible coffee seedlings should be delayed at least for
2 years Girma . Cultural weed control activities like slashing
and digging should be avoided in CWD-prone coffee fields, and
agronomic practices (pruning and stumping) that bring about
wounding in coffee trees should be done with efficiently disinfected
tools. Disinfection of farm implements such as machetes, bow
saws and pruning shears with potent disinfectants (>75% alcohol)
followed by intense heating with fire is strongly recommended
to farmers whenever pruning, rejuvenating old coffee trees and
thinning newly suckers. Farmers’ field schools recommend growing
cover crops such as Desmodium sp. and haricot bean, which
are very efficient in suppressing weeds (so reducing the need for
slashing) and as legumes, promote the growth of coffee trees. Applying
ash, mulch and slashing between plots with hand weeding
around coffee trees were also promising treatments in CWD control
trials CABI .
The first step taken in this direction
was training of both extension staff and farmers in disease
recognition, followed by sensitization of fanners and civic leaders.
Sanitary control measures were then implemented which include:
a) Regular inspection and destruction of affected trees by
cutting trees at ground level, chopping and burning in situ.
b) Uprooting and burning of the entire plant produces best
results. Neighboring trees should be cut back and thick mulch
c) Diseased trees when left standing in the field continue
to discharge spores to neighboring or distant trees for several
d) Destruction of dead or severely diseased trees proceeded
by superficial burning of the upper parts before any handling/
uprooting trees assists in reducing dispersal of spores.
e) Wounding trees should be avoided, since wounds provide
entry points for the pathogen.
f) Restriction of movement of infected plants as firewood,
coffee husks and kiboko from infected areas to other areas.
g) Restriction of movement of planting materials from infected
to non-infected areas.
h) Banning the use of coffee husks as mulch in coffee fields,
as a precaution.
i) Vse of volunteer seedlings from forests on infected coffee
plantations is discouraged. Seedlings from infested plantations
may harbours the disease without showing obvious
j) Milling coffee should be done in the district of production.
k) Continuous surveillance of disease in all coffee growing
areas to keep track of spread and ascertain the effectiveness of
l) Training and sensitization of all stakeholders on dangers
of the disease etc.
Biological control is the reduction of inoculums
density or disease producing activities of a pathogen or
parasite in its active or dormant state, by one or more organisms
accomplishing naturally or through manipulation of the environment,
host or antagonists, or by mass introduction of one or more
antagonist. Biological control is the strategy for reducing disease
incidence or severity by direct or indirect manipulation of microorganisms
(Tesfaye and Kapoor, 2004). Antagonists that produce
antibiotics kill pathogens and eradicate or control them from
substrate. Some microorganisms occupy the niches and exclude
pathogens from becoming established, thereby protecting plants
from infection. Biological control has attracted great interest because
of increasing regulation and restriction of fungicides or unnecessary
control attempts by other means . It is especially attractive
for soil borne diseases because it needs critical evaluation
of economics of the country and the pathogens that are difficult to
reach with specific fungicides. The result of a recent in vitro study
conducted by Muleta & Negash on antagonistic effects of some rhizobacteria
and Tricoderma isolates against the F. xylarioides were
promising. Of 23 bacterial isolates obtained from rhizospheres of
arabica coffee trees in south-west Ethiopia, 21 significantly inhibited
the mycelial spread of F.xylarioides. Bacillus subtilis, designated
as isolate ‘AUBB20’, was the most antagonistic to this pathogen.
T. viride and T.harzianum has shown good potential in inhibiting
the mycelial growth of F. xylarioides
Fungal diseases of coffee are the major
constraints to reduce coffee production and quality in major coffee
producing countries of Africa. Next to Coffee Berry Disease
(CBD) the most limiting factors for coffee production in Central
and East African countries is tracheomycosis or vascular wilt disease
of coffee caused by Fusarium xylarioides Steyaert imperfect
stage (Gibberella xylarioides Heim and Saccas Perfect stage). The
major difference between tracheomycosis and many other coffee
diseases is that it kills all affected trees at all stages of development.
The fungicides were sprayed at the rates, schedules and
combinations indicated in (Table 1) . Three fungicides, Ridomil
Gold (metalxyl 8%+ Mancozeb 64%) 68% Wp 2.5kg/ha with protective and curative action and Pencase 80% WP (Mancozeb)
at the rate of 2.5kg/ha (Cornell University, 1988) with protective
action and Novel was used systemic at the rate of 2.5kg/ha coffee
wilt disease effectively control. Spraying was performed by using
manually pumped knapsack sprayers of 20 litter’s capacity .
During fungicide spraying using surrounded by plastic sheet in order
to avoid spray drift to adjacent area. Fungicide spray intervals
weekly (7day), biweekly (14day), three weekly (21) and 28day
intervals until maturity. The intervals between successive sprays
were constant week when diseased symptoms occurred. The data
on disease severity recorded one day before spray and 7 days after
spraying using, sprayed at early flowering and fruit setting (Table
2). The Spraying started soon after the appearance of coffee wilt
Prospects for long term control measures depend on research
activities, which will be implemented to generate information on: -
I. Epidemiology and biology of the pathogen, to cover mode
of spread and transmission, survival, presence of alternate
hosts particularly, major food crops generally intercropped
II. Host plant resistance/tolerance is being explored by
inoculation of all available germplasm, breeders’ materials
and current recommended arabica and Robusta varieties.
The same materials are also planted out on farmers’ fields where coffee has been destroyed by wilt. Before release to
farmers, it is essential to screen all materials for resistance to
III. The effects of production systems (intercropping, soil
fertility management and cultivation on non-host crops for
5 or more years followed by coffee) on wilt incidence and
severity will be elucidated. The role of weather factors e.g.
rainfall, temperature. etc. as well as soil types, effect of organic
manures, are also to be assessed and correlated to wilt
IV. The role played by other Fusarium species found
associated with F. xylarioides needs to be clearly spelt out.
V. Factors responsible for the appearance and
disappearance of wilt disease are to be investigated
VI. The use of biocontrol agents e.g. a strain of Fusarium
oxysporum to suppress Fusarium and use of systemic fungicides
as drench in planting holes etc. are to be investigated. These
could find use for spot treatments on large plantations where
the fanners have invested a lot of money.
VII. Collaboration in research at regional and international
levels needs to be strengthened in order to speed up progress
through exchange of intonation, resistant materials etc. These wiII eventually provide information required for formulation
of an integrated control procedure
Currently in Ethiopia most coffee trees are less productive because
of variable factors, among that diseases are the major constraints
which threatening coffee genetic resources. These major
diseases are coffee leaf rust, coffee wilt disease and coffee berry
diseases are becoming important and that occurs with varying
degree of infestation and distribution in the main area of Ethiopia.
Thus, the forest coffee conservation strategies should take
the disease into account and apply the recommended principles
and practices of disease management. This economic loss coupled
with difficulty to manage the disease indicates that CWD is the second
leading disease of coffee, after CBD in Ethiopia and the most
distractive coffee production threat without any solution till now.
The soil-borne nature of the pathogen and perennial character of
coffee have made management of the disease difficult through the
conventional control approach of ‘uproot and burn infected trees
at the spot.
Development of resistant coffee varieties through large-scale
collection and screening against the pathogen would be inevitable,
although it seems that most coffee trees exhibit susceptibility in
the forest coffee populations. Investigation in the area of developing
resistant varieties, biocontrol agents, use of proper cultural
practices and screening effective chemicals as a last resort or use
of these techniques in integrated pest and disease management
strategy could minimize the damage caused by diseases and would
definitely conserve coffee genetic pools and facilitate utilization of
coffee genetic resources at their place of origin in natural rainforests
for global benefits. It is important that prior to their release
to coffee growers, resistant coffee types should also be tested for
their level of resistance to those diseases particularly coffee wilt
and coffee leaf rust. Therefore, employing effective, easily applicable,
environmentally sound and economically feasible control approaches
should be exercised for disease management of Arabica
coffee in forest populations of Ethiopia.
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